164 research outputs found
Absence of Fas-L aggravates renal injury in acute Trypanosoma cruzi infection
Trypanosoma cruzi infection induces diverse alterations in immunocompetent cells and organs, myocarditis and congestive heart failure. However, the physiological network of disturbances imposed by the infection has not been addressed thoroughly. Regarding myocarditis induced by the infection, we observed in our previous work that Fas-L-/- mice (gld/gld) have very mild inflammatory infiltration when compared to BALB/c mice. However, all mice from both lineages die in the early acute phase. Therefore, in this work we studied the physiological connection relating arterial pressure, renal function/damage and cardiac insufficiency as causes of death. Our results show that a broader set of dysfunctions that could be classified as a cardio/anaemic/renal syndrome is more likely responsible for cardiac failure and death in both lineages. However, gld/gld mice had very early glomerular deposition of IgM and a more intense renal inflammatory response with reduced renal filtration, which is probably responsible for the premature death in the absence of significant myocarditis in gld/gld.Instituto Oswaldo Cruz-Fiocruz Laboratório de Biologia CelularUniversidade Federal do Rio de Janeiro Instituto de Biofísica Carlos Chagas FilhoUniversidade Federal Fluminense Instituto Biomédico Departamento de Fisiologia e FarmacologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de NefrologiaCentro de Criação de Animais de Laboratório Departamento de Controle de Qualidade AnimalUNIFESP, EPM, Disciplina de NefrologiaSciEL
Insights into Candida tropicalis nosocomial infections and virulence factors
Candida tropicalis is considered the first or the second non-Candida albicans Candida (NCAC) species most frequently isolated from candidosis, mainly in patients admitted in intensive care units (ICUs), especially with cancer, requiring prolonged catheterization, or receiving broad-spectrum antibiotics. The proportion of candiduria and candidemia caused by C. tropicalis varies widely with geographical area and patient group. Actually, in certain countries, C. tropicalis is more prevalent, even compared with C. albicans or other NCAC species. Although prophylactic treatments with fluconazole cause a decrease in the frequency of candidosis caused by C. tropicalis, it is increasingly showing a moderate level of fluconazole resistance. The propensity of C. tropicalis for dissemination and the high mortality associated with its infections might be strongly related to the potential of virulence factors exhibited by this species, such as adhesion to different host surfaces, biofilm formation, infection and dissemination, and enzymes secretion. Therefore, the aim of this review is to outline the present knowledge on all the above-mentioned C. tropicalis virulence traits.The authors acknowledge Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazil, for supporting Melyssa Negri (BEX 4642/06-6) and Fundacao para a Ciencia e Tecnologia (FCT), Portugal, for supporting Sonia Silva (SFRH/BPD/71076/2010), and European Community fund FEDER, trough Program COMPETE under the Project FCOMP-01-0124-FEDER-007025 (PTDC/AMB/68393/2006) is gratefully acknowledged
High interannual variability in connectivity and genetic pool of a temperate clingfish matches oceanographic transport predictions
Adults of most marine benthic and demersal fish are site-attached, with the dispersal of their larval stages ensuring connectivity among populations. In this study we aimed to infer spatial and temporal variation in population connectivity and dispersal of a marine fish species, using genetic tools and comparing these with oceanographic transport. We focused on an intertidal rocky reef fish species, the shore clingfish Lepadogaster lepadogaster, along the southwest Iberian Peninsula, in 2011 and 2012. We predicted high levels of self-recruitment and distinct populations, due to short pelagic larval duration and because all its developmental stages have previously been found near adult habitats. Genetic analyses based on microsatellites countered our prediction and a biophysical dispersal model showed that oceanographic transport was a good explanation for the patterns observed. Adult sub-populations separated by up to 300 km of coastline displayed no genetic differentiation, revealing a single connected population with larvae potentially dispersing long distances over hundreds of km. Despite this, parentage analysis performed on recruits from one focal site within the Marine Park of Arrabida (Portugal), revealed self-recruitment levels of 2.5% and 7.7% in 2011 and 2012, respectively, suggesting that both long-and short-distance dispersal play an important role in the replenishment of these populations. Population differentiation and patterns of dispersal, which were highly variable between years, could be linked to the variability inherent in local oceanographic processes. Overall, our measures of connectivity based on genetic and oceanographic data highlight the relevance of long-distance dispersal in determining the degree of connectivity, even in species with short pelagic larval durations
Enhancement of nematic order and global phase diagram of a lattice model for coupled nematic systems
We use an infinite-range Maier-Saupe model, with two sets of local
quadrupolar variables and restricted orientations, to investigate the global
phase diagram of a coupled system of two nematic subsystems. The free energy
and the equations of state are exactly calculated by standard techniques of
statistical mechanics. The nematic-isotropic transition temperature of system A
increases with both the interaction energy among mesogens of system B, and the
two-subsystem coupling . This enhancement of the nematic phase is manifested
in a global phase diagram in terms of the interaction parameters and the
temperature . We make some comments on the connections of these results with
experimental findings for a system of diluted ferroelectric nanoparticles
embedded in a nematic liquid-crystalline environment.Comment: 11 pages, 3 figures, to appear in Volume 42 of the Brazilian Journal
of Physic
Operation and performance of the ATLAS Tile Calorimeter in Run 1
The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report
Search for single production of vector-like quarks decaying into Wb in pp collisions at √s = 8 TeV with the ATLAS detector
A search for singly produced vector-like Q quarks, where Q can be either a T quark with charge +2/3 or a Y quark with charge −4/3, is performed in proton–proton collisions recorded with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 20.3 fb −1 and was produced with a centre-of-mass energy of √s = 8 TeV. This analysis targets Q→Wb decays where the W boson decays leptonically. A veto on massive large-radius jets is used to reject the dominant tt̄ background. The reconstructed Q-candidate mass, ranging from 0.4 to 1.2 TeV, is used in the search to discriminate signal from background processes. No significant deviation from the Standard Model expectation is observed, and limits are set on the Q→Wb cross-section times branching ratio. The results are also interpreted as limits on the QWb coupling and the mixing with the Standard Model sector for a singlet T quark or a Y quark from a doublet. T quarks with masses below 0.95 TeV are excluded at 95 % confidence level, assuming a unit coupling and a BR(T→Wb)=0.5, whereas the expected limit is 1.10 TeV
Teamwork in a coronary care unit: facilitating and hindering aspects
Abstract OBJECTIVE To identify, within a multidisciplinary team, the facilitating and hindering aspects for teamwork in a coronary care unit. METHOD A descriptive study, with qualitative and quantitative data, was carried out in the coronary care unit of a public hospital. The study population consisted of professionals working in the unit for at least one year. Those who were on leave or who were not located were excluded. The critical incident technique was used for data collection, by means of semi-structured interviews. For data analysis, content analysis and the critical incident technique were applied. RESULTS Participants were 45 professionals: 29 nursing professionals; 11 physicians; 4 physical therapists; and 1 psychologist. A total of 49 situations (77.6% with negative references); 385 behaviors (54.2% with positive references); and 182 consequences emerged (71.9% with negative references). Positive references facilitate teamwork, whereas negative references hinder it. A collaborative/communicative interprofessional relationship was evidenced as a facilitator; whereas poor collaboration among agents/inadequate management was a hindering aspect. CONCLUSION Despite the prevalence of negative situations and consequences, the emphasis on positive behaviors reveals the efforts the agents make in order to overcome obstacles and carry out teamwork
Climate change and outdoor regional living plant collections: an example from mainland Portugal
Original PaperClimate change threatens not only plant species occurring naturally, but also
impacts on regional living plant collections, which play an important role in ex situ
conservation strategies. In the last few years, several global circulation models have been
used to predict different global climate change scenarios. Due to their coarse resolutions,
and while more detailed regional approaches are not available, downscaling techniques
have been proposed, as a very simple first approach to increase detail. We analysed seven
sites on mainland Portugal with potential for species conservation (four botanic gardens
and three universities), in the light of downscaled climate change scenarios, using an
environmental envelope approach and a predefined bioclimatic neighbourhood for each
site. Thresholds for the bioclimatic neighbourhood were based on Rivas-Martı´nez’s Bioclimatic
Classification of the Earth. For each site, the expected geographical shift of its
original bioclimatic neighbourhood (1950–2000) was mapped for 2020, 2050 and 2080.
Analysing those shifts enabled us to delineate knowledge-transfer paths between sites,
according to the analysed scenarios. We concluded that, according to the Intergovernmental
Panel on Climate Change A2 scenario, all considered sites will be outside the
predefined bioclimatic neighbourhood by 2080, while according to the B2 scenario all of
them will be inside that neighbourhood, although sometimes marginally so. Therefore, the
implementation of global sustainability measures as considered in the B2 scenario family
can be of great importance in order to delay significantly the impacts of climate change,
giving extra time for the adaptation of the outdoor regional living plant collectionsinfo:eu-repo/semantics/publishedVersio
Zika virus in the Americas: early epidemiological and genetic findings
Brazil has experienced an unprecedented epidemic of Zika virus (ZIKV), with ~30,000 cases reported to date. ZIKV was first detected in Brazil in May 2015, and cases of microcephaly potentially associated with ZIKV infection were identified in November 2015. We performed next-generation sequencing to generate seven Brazilian ZIKV genomes sampled from four self-limited cases, one blood donor, one fatal adult case, and one newborn with microcephaly and congenital malformations. Results of phylogenetic and molecular clock analyses show a single introduction of ZIKV into the Americas, which we estimated to have occurred between May and December 2013, more than 12 months before the detection of ZIKV in Brazil. The estimated date of origin coincides with an increase in air passengers to Brazil from ZIKV-endemic areas, as well as with reported outbreaks in the Pacific Islands. ZIKV genomes from Brazil are phylogenetically interspersed with those from other South American and Caribbean countries. Mapping mutations onto existing structural models revealed the context of viral amino acid changes present in the outbreak lineage; however, no shared amino acid changes were found among the three currently available virus genomes from microcephaly cases. Municipality-level incidence data indicate that reports of suspected microcephaly in Brazil best correlate with ZIKV incidence around week 17 of pregnancy, although this correlation does not demonstrate causation. Our genetic description and analysis of ZIKV isolates in Brazil provide a baseline for future studies of the evolution and molecular epidemiology of this emerging virus in the Americas
Fuel Mix Characteristics and Expected Stock Returns of European Power Companies
This article investigates the impact of the fuel mix structure in power generation portfolios on expected stock returns for major European power companies. The 22 biggest publicly listed European power producers are examined between January 2005 and December 2010. Based on the capital asset pricing model (CAPM) and multi-factor market models, the systematic risk of the power companies relative to the overall market performance and other typical energy and macroeconomic risk factors is analyzed. The full-information approach is used to determine technology-specific betas and risk factor sensitivities from the sample. Although most companies are not exclusively in the power producing business, it is shown that the generation fuel mix has a significant impact on the historical stock returns of the investigated companies. In particular, the sample companies exhibit significant differences in the systematic risk of gas and nuclear generation technologies compared with renewable technologies measured by technology-specific, delevered beta factors. This study extends existing literature and contributes new insights in two ways: Firstly, this is to our knowledge the first empirical analysis comparing the financial risk of different electricity generation technologies. Secondly, the results provide practical benefit to determine adequate riskadjusted capital costs for typical generation technologies. Therewith, this study is relevant for evaluating all kinds of power plant investments
- …
